Track-gage



(No Model.) Y I' 2 Sheets-Sheet; l,

. o. E. IRWIN.

A TRACK GAGE. No. 577,580. g Patented Feb. 23, 1897.

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0.1.. IRWIN.

TRACK GAGE.

No.577,5ao. PatentedPeb.z3,-1a97.

. IINTTED YSTATES FATENT OFFICE.

CLARENCE E. IRVIN, OF ST. LOUIS, MISSOURI.

TRACK-GAG E.

SPECIFICATION forming part of Letters Patent No. 577,580, dated February23, 189'?.

Application filed April 4, 1896. Serial No. 586,205. (No model.)

To a/ZZ whom t may concern:

Be it known that I, CLARENCE E. IRWIN, a citizen of the United States,residing at the city of St. Louis, State of Missouri, have invented acertain new and useful Improvement in Track-Gages, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, forming a part of this specification,wherein- Figure 1 is a side-elevational View of my improved track-gagein position on a track, showing the same used as an ordinarystandard-gage. Fig. la is a fragmentary top plan view of the gage. Fig.2 is a side-elevational view showing my improved gage in position on acurve.- Fig. 3 is an enlarged top plan view illustrating the bracket andits guideway. Fig. 4L is a detail view of the adjustable bracket. Fig. 5is a view illustrating the several scales, and Fig. 6 is a viewillustrating the manner of using my improved track-gage on a curve.

This invention relates to a new and useful improvement in track-gages,the objects being to construct a gage by which can be determined, iirst,the degree of curvature of an unknown curve; second, the elevation to begiven the outer rail or which the outer rail should have in any curve;third, the middle ordinate of a cord by which the radius may bedetermined, and, fourth, the widening of the rails for curves toaccommodate the fixed wheel-base of rigid trucks.

Vith these objects in view the inventio consists in 4arranging a numberof suitable scales on the gage, which scales are adapted to coperatewith a chord made by a line, such as a tape-measure, which indicates atits point of contact with the gage in respect to the scales the degreeof the particular curvel bein g measured, the height to which the outerrail in that curve should be raised or should occupy to comply with thestandard table of elevations for given curves and the middle ordinatefora given length of chord of the curve being measured.

The invention further consists in arranging an adjustable foot orbracket at one end of the gage,whereby when the elevation which theouter rail should occupy has been established this bracket can beadjusted accordingly, and should the outer rail not reach that level itcan bebuilt up to the required level, which is determined by aspirit-level arranged on the gage. Incidentally this feature of theinvention involves another important factor in the construction ofrailroadcurves, and that is the widening of the gage to accommodate thewheel -base of rigid trucks. This is one of the results flowing from theuse of-a gage such as I have shown, and I therefore claim it as myinvention.

Other minor details of the invention reside in the construction,arrangement, and combination of the several parts all to be hereinafterdescribed, and afterward pointed out in the claims.

In the drawings, A indicates an vordinary standard track-gage, havingthe usual seats or recesses at its ends to cooperate with the rails todetermine their proper distance apart. One of these seats is movable oris formed as an adj ust-able bracket B, mounted in a suitable guideway,said bracket being preferably slotted to receive binding-screws b, whichhold the bracket in adjusted positions, although there are other formsof locking devices for this bracket which could as advantageously beused. This bracket is provided with a scale, preferably in inches,starting from a iiXed Zero-point on the gage when the bracket is in itsnormal position or home and running up the Vertical member of thebracket eight or nine inches, as shown in Fig. 1. It will of course beunderstood that the scope of adjustment of this bracket and this scalecould be increased as much as desired, but nine inches has been foundsufiicient for ordinary usage.

C indicates a spirit-level whose use and operation are well understood.This spirit-level is preferably located on the top of the gage, aboutits middle.

D indicates a scale which I will term the degree-of-curve scale and ismarked with points which indicate the degree of curve in a given arcfrom a tangent, said arc havinga given chord. This scale is used to savethe trouble of a trigonometrical survey if such has never been made.

IOO

E indicates a scale which is marked with points, preferably in inches,which indicates the distance between the crown of the arc being measuredor the outer rail and the chord of the same or the length of the middleordi* nate.

F indicates a scale which is marked with points to indicate theelevation which the outer rail should occupy to conform to the standardof elevation for outer rails in given curves. It is by this scale thatthe bracket B is adjusted.

The operation of the device is as follows: As shown in Fig. l, thedevice can be used as an ordinary standard track-gage. W'e will assume,however, that the track in Fig. 1 is on a curve whose degree, cbc., isunknown and it is desired to have the same conform to the standard ofcurves. A tape-line or other cord or chain, whose length in cooperationwith my improved gage has been predetermined and the scales madeaccordingly, is placed upon the inneredge of the outer curved rail andforms a chord of which the rail is the arc, as shown in Fig. 6. I willassume that this tape-measure is fifty (50) feet long and that thetwenty-live (25) foot mark is located immediately above my track-gage inposition. The tape-measure is stretched taut and the scales read. Wewill assume that zo in Fig. 5 indicates the tape-measure- The readingsof the scales will show that it is a five-degree curve, that the outerrail should be elevated four and one-half inches, and that the length ofthe middle ordinate, or the distance between the arc or outer rail andthe chord or tape-measure, is about three and three-eighths inches.These figures can be employed in reports, rbc. Having ascertained this,the next thing to do is to elevate the outer rail to the heightindicated by the scale. To do this, the bracket B is adj usted downuntil its four and one-half inch mark is opposite the Zeromark on thegage and the binding-screws b tightened. The outer rail is now raised,as shown by the dotted lines in Fig. 2, until the spirit-level readingshows that it has reached the proper elevation. In elevating this outerrail by the use of the laterally, or, I might say, the verticallyadjustable bracket, the gage of the rails is widened in proportion tothe square of the altitude, which, we will say, is represented by thesquare of the dotted line extending from points a to c, plus the squareof the base, which, we will say, is represented by the square of thedotted line extending from point c to point d, which combined squaresequal the square of the length of the hypotenuse,or the distance betweenthe points a and el. The less the degree of curvature, the less will bethe Widening of the gage, as the bracket will be lowered very little andthe base of this triangle lessened accordingly, while the shorter theradius of the curve or the greater the degree of curve the more thebracket will be lowered, and consequently this base will be lengthened,making the hypotenuse of the right-angle triangle so formed, or thedistance between the rails, greater.

I am aware that many minor changes in the construction, arrangement, andcombinations of the various parts of my device can be made andsubstituted for those herein shown and described without in the leastdeparting from the nature and principle of the invention.

I-Iaving thus described the invention, what I claim as new, and desireto secure by Letters Patent, is-

1. A track-gage for determining the degree of curvature of atrack-curve, said gage having a scale arranged thereon near the endwhich cooperates with the outer rail, and with a cord or tape-measurewhich is adapted to be placed on the outer rail on each side of saidgage; substantially as described.

2. In a track-gage for railroad-curves, the combination with the bodyportion of the gage, a scale on said body portion for determining theelevation which the outer rail of the curve being measured, shouldoccupy, and a cord or tape-measure for cooperating with said scale;substantially as described.

3. In a track-gage for railroad-curves, the combination with the bodyportion of the gage, a scale on said body portion for determining theelevation which the outer rail of the curve being measured, shouldoccupy, a cord or tape-measure for cooperating with said scale, anadjustable bracket on the end of said body portion, and a spirit-levelarranged in said body portion 5 substantially as described.

4. In a track-gage for railroad-curves, the combination with the bodyportion of the gage, a scale on said body portion for determining theelevation which the outer rail of the curve being measured, shouldoccupy, a scale on said body portion for determining the degree ofcurvature, and a cord or tapemeasure for cooperating with said scales,substantially as described.

5. In a track-gage for railroad-curves, the combination with the bodyportion of the gage, a scale on said body portion for determinin theelevation which the outer rail of the curve being measured, shouldoccupy, a scale on said body portion for determining the degree ofcurvature, a scale on said body portion for determining the middleordinate, and a cord or tape-measure for cooperating with said scales;substantially as described.

6. The combination with the body portion of a track-gage, which gage isdesigned to be used on curves and in connection with a cord ortape-measure, of a scale on said body portion which is adapted tocooperate with the cord or tape-measure for determining the elevationwhich the outer rail of the curve should occupy, a vertically-slottedbracket which is adjustably mounted on one end of the body portion ofthe gage, said bracket IIO IZO

having a scale on its vertical member by signature, in presence of twoWitnesses, this which it is adjusted, a rail-seat on the lower 14th dayof March, 1896. end of the bracket, and a sprtdevel for establishng theproper elevation of the outer 4 CLARENCE E' IRWIN' 5 rail afterthebraoket has been adjusted; sub- Witnesses:

stantally es described. HUGH K. WAGNER,

In testimony whereof I hereunto afx my F. R. CORNWALL.

